I know that there are a large chunk of the female sex who enjoy having sex, but have never had an orgasm. Did Kinsey or any other sexologist ever determine what percentage of woman have never had orgasms?

In 1981, The Hite Report revealed that 26% of the three thousand women who participated in the study experienced orgasm regularly during vaginal intercourse, when there was no accompanying manual stimulation of their clitoris. While this study is nearly twenty years old, I have not seen any evidence that would indicate this number has changed drastically during that time period. The study also found that: 19% of the participating women rarely experienced orgasm during intercourse, 16% did so if there was manual stimulation of their clitoris at the same time, and 24% did not experience orgasm during intercourse at any time. In addition, 12% of the women had never experienced orgasm under any condition, and 3% had never engaged in intercourse. That means roughly eight out of every ten women did not experience orgasm as the result of vaginal stimulation alone.

It could possibly be something as simple as blood flow in the region. I believe I remember reading what appeared to be a scientific article about women who had never had an orgasm suddenly being able to have one while they were pregnant.

The Hite Report was blasted as being wildly unscientific and unreliable in its methodology when published, and has been criticized ever since.

This criticism is based on the assumption that Shere Hite actually used the methodology she described. Some years after its initial publication, an ex-boyfriend of Hite's and some of his friends claimed that they made up most of the questionnaire answers, and, if IIRC, were fairly drunk a good deal of the time as they did so.

Hite (a former Playboy model who isn't really named Shere Hite), ran into further embarassment when reporters for national publications tried to interview her about these allegations. Her maid kept telling them that Ms. Hite wasn't home. The only thing is, as Time and/or Newsweek reported at the time, some of the reporters were ready to swear that the maid was Ms. Hite, pretending that she wasn't.

By and large, The Hite Report appears to be what it was marketed as: an instance of what Playboy Magazine in its premiere issue called "pious pornography"; a chance to read tittilating material, aimed at women readers, presented as pop social science. (Of course Playboy has printed its share of that over time as well, in addition to more honest forms of porn.)

None of which, of course, answers the OP, but does suggest that one ought to go to some source besides The Hite Report for data.